The existing locksets used in safety boxes are generally mechanical locks or electronic locks. The mechanical coded locks include ordinary mechanical coded locks and highly-secure mechanical coded locks. For the ordinary mechanical coded lock, a small quantity of codes are applicable and the security is poor. For the highly-secure mechanical coded lock, a large quantity of codes are applicable and the security is good, but the operations, for example, code entering and code changing, are complicated, resulting in poor usability. An electronic coded lock has a large number of electronic devices, leading to a complex structure and high fault rate; besides, the electronic devices should be protected against moisture, strong magnetoelectricity, and strong vibration, putting certain requirements on the operating environment. The mechanical locks may easily avoid these disadvantages by taking some measures. A faulty electronic lock may cause great inconvenience to a user and is inconvenient to fix, such that the user can do nothing but nail-biting. Many electronic locks have backup mechanical unlocking means (for an emergency), which undoubtedly decreases the security of the locksets.
An early-stage electronic lock is generally powered by the mains supply and is power consuming. An existing integrated circuit electronic lock consumes a little power, where a button cell can maintain the operation of a control part, but an electromagnet or a motor needs to be actuated with a larger battery or the mains supply. On the contrary, the problem does not need to be considered for the mechanical lock. In spite of the above problem, the electronic lock has advantages of a large quantity of codes and key-free operation.
An electronic lock has apparently higher security than a mechanical lockset in avoiding technical unlocking, because the mechanical lockset can be easily technically opened within a short period of time, while the electronic lock is hard to be technically opened within a short period of time. However, the electronic lock has many problems. For example, the codes may be easily forgotten or leaked due to improper safekeeping, the battery of the electronic lock runs out, or a fault occurs in the devices of the electronic lock. Whenever such problems occur, the electronic lock can only be opened through destructive unlocking in most cases.
Therefore, in recent years, a mechanical lock is usually adopted as a mechanical backup lock of an electronic lock, to solve the above problems in the electronic lock. However, an existing electronic-mechanical lock has a small quantity of codes and poor capability of preventing technical unlocking, is complex in structure and operation, and is unstable in switching between an electronic unlocking mode and a mechanical unlocking mode.